As cell phones with cameras in which a camera is mounted have become popular in recent years, chances photographing various objects to be photographed by using the cell phone have increased. For example, there is a case that an object such as a friend or landscape which is apart from a lens of a camera to some extent is photographed (normal photographing) and, alternatively, there is a case that an object such as a timetable for bus or petals of a flower at a position near the lens of the camera is photographed (close-up photographing).
In the close-up photographing (macro-photographing), a lens position of a camera is required to locate at a position nearer on an object side than a lens position at the time of normal photographing. Therefore, this type of photographing lens system is provided with a drive mechanism for driving a lens to move in the optical axis direction. The drive mechanism is driven by changing a switch to move a lens in the optical axis direction (see, for example, Japanese Patent Laid-Open No. 2007-94364).
The lens drive device which is disclosed in the above-mentioned Patent Reference includes a movable lens body, a drive mechanism for moving the movable lens body in an optical axis direction, a fixed body which movably supports the movable lens body in the optical axis direction, and a restriction means (plate spring) for restricting movement of the movable lens body. The drive mechanism includes a magnet and a coil. In the structure as described above, while an electric current is supplied to the coil to generate an electromagnetic force, a restriction force against the electromagnetic force is generated by the restriction means. Magnitudes of both the restriction force and the electromagnetic force are adjusted to be capable of stopping the movable lens body at a desired position.
In this structure, the above-mentioned restriction means (plate spring) also functions as an electrical contact with an external apparatus (for example, a cell phone with camera) into which the lens drive device is assembled. The restriction means which functions as the electrical contact is commonly disposed at a lower end of the lens drive device (image sensor element side). When the coil is structured so that the coil is divided into two upper-and-lower layers, at first, for example, a coil has been wound around for a lower layer and next, the oil is wound around for an upper layer. For a winding start portion in the lower layer, a successively winding wire is wound around on the wire which has been wound first and thus the winding start portion hardly come loose.
However, for a winding end portion in the upper layer, different from the winding start portion in the lower layer, there is no holding part for the wire and thus the winding end portion comes loose easily.
In other words, in a case that the coil has a structure divided into two upper-and-lower layers, in order to connect a lower layer coil to an upper layer coil, the lower layer coil is wound around so as to be formed in an odd-number of layers toward an outer side in a radial direction of the movable lens body (movable body). In addition, when the same number of layers is wound around for both the upper layer and the lower layer in order to generate substantially the same electromagnetic force in the upper layer and the lower layer, a winding end portion of the upper layer coil is located on an opposite side to a winding start portion (near an upper end of the movable lens body). In this case, when the winding end portion of the coil is temporarily fixed with an adhesive or the like and then the winding end portion of the coil is drawn to the lower part of the movable lens body, the winding end portion may easily come loose. On the contrary, when the coil is firstly wound around on the upper layer side, the winding start portion may become loose easily. Further, this problem may also occur in a structure that the coil is not divided into the two upper-and-lower layers.